A conventionally used valve body, as shown in FIGS. 1, 2, of the bathtub cold-hot water valve system, comprises housing A, ceramic valve B, operation bar C, angle controller D. Housing A is shaped by main barrel E to which water inlet barrel F is screwed through threads, and contains ceramic valve B and part of operation bar C, the operation bar's angle controller D being a spring pin to meet a pinhole in operation bar C and extend into the holding cross groove G of main barrel E, in order to control the turning angle of operation bar C and have its front and rear sides positioned.
In assembling to housing H of the bathtub cold-hot water valve system, housing A with male threads, by means of packing ring J, could be just screwed together with housing H with female threads, making the water inlet barrel F, which has sealing ring K set around its front, inserted the water source pipe. Therefore, after sealing ring K united to the water source pipe wall, water supply shall come from inlet L of water inlet barrel F to the front of ceramic valve B to be ready for use. At time of use, turning operation bar C may bring ceramic valve B to work, so the water from inlet L is expected to go through ceramic valve B to outlet M, available on both lateral sides of main barrel E, to flow out by way of the drainage pipe N of housing H.
Since the above-said conventional valve body had its patent, factory production began and a number of this kind of valve body has been shipped to many countries for sale for years and received good reputation. However, after years' use, a few of them were found to have water leak and destruction problems. And after research, analysis, and inspection on some defective samples, there are findings regarding the cause:
1. The surface of sealing ring K, set around water inlet barrel F outside, occurs with scrapes and resilience fatigue, which scrapes are probably caused by turning water inlet barrel F for assembly, to cause water in the water source pipe to permeate and leak in drops out of drainage pipe N.
2. The threads adaption between main barrel E and water inlet barrel F is imperfect, as a result, let the water has space to permeate and drop out of drainage pipe N.
3. Sealing ring O, set behind water outlet M, occurs with scrapes, so the water passing outlet M may permeate into angle controller D to rust and corrode the spring pin and make it broken down eventually.